generic emerger pattern

I need a "go to" emerger pattern to use as a dropper off a dry fly. I would like to have a size 20 or 18 simple to tie pattern that works more often then not. I am not looking for a specific match the hatch type fly but one that generally works most of the time.

I'll have to cast my vote with the above mentioned fly (deer hair emerger), too...have tied and used it with more than satisfactory results, and it's reasonably easy to tie, too.
When I have used it as the floating fly for a dropper rig my strikes have been on the nymph, though...

I have tied up a emerger very much like the one shown with the exeption that instead of a deer hair wing I tie a parachute wing then after its all tied in good force the hackle upward and wrap the hackle at the base to force it up so that it stands up like the deer hair, I then put in a little head cement to keep the hackle up and make the fly stronger. The results are almost alike. One bonus with this way of tying is I can make the post a high vis so my eyes can see on the water better.

A K.F. FLASHER IN EITHER BLACK, BROWN OR RED WORKS REALLY WELL. IF YOU DON'T KNOW WHAT A K.F. FLASHER IS, IT'S A THREAD BODY OF THE COLORS MENTIONED A FINE GOLD WIRE RIBBING, A COUPLE STRANDS OF RAINBOW CRYSTAL FLASH TRIMMED SHORT, RIGHT BEHIND THE HEAD, AND A BLACK DUBBING HEAD. GREAT PATTERN

About 12 years ago I designed a simple, all-purpose emerger that I call the Deerhair Emerging Whatever. Instead of a bug "struggling with its tights," I visualize someone struggling with a pullover sweater: during the moments when the sweater covers and engulfs the wearer's head and arms, the wearer looks like everyone, but nobody in particular. Anyway, that's the concept. This fly has performed in many situations, when insects of all major orders were emerging.
On a light-wire hook, tie in a shuck consisting of those dun-colored soft fibers that grow at the base of many of the feathers we fly-tiers use; slightly less than shank length. Next, dub a body: your choice of color and texture. Then stack a slim bundle of deer hair. Tie it in about 1/4 shank length behind the eye (just in front of the body), tips forward, ca. one shank length protruding. Divide the tips, pull each half out to the side, 90 degrees from the shank; figure-eight them into place. Now take the deerhair that's to the rear, and make a hump (it's easier to wrap the bundle forward over your bodkin or scissor points). Tie down the deer hair behind the eye and trim the excess. You can add head-dubbing for larger hooks.
This fly is easier and faster to tie than it was to write the above description. It may not be better than the above Klinkhamer variation, which I'm now eager to try, but it ably serves my needs for an all-purpose emerger.